U.S. patent number 4,557,998 [Application Number 06/688,224] was granted by the patent office on 1985-12-10 for colorless ligand-releasing monomers and polymers and their use to provide dyes with metal ions.
This patent grant is currently assigned to Eastman Kodak Company. Invention is credited to Kenneth R. Hollister, William N. Washburn.
United States Patent |
4,557,998 |
Washburn , et al. |
December 10, 1985 |
Colorless ligand-releasing monomers and polymers and their use to
provide dyes with metal ions
Abstract
Essentially colorless, hydrophilic ligand-releasing polymers are
prepared from ethylenically unsaturated polymerizable monomers
represented by the structure: ##STR1## wherein R' is hydrogen or
lower alkyl, COUP is a photographic color coupling moiety, LINK is
a coupling-off group which can be cleaved by an oxidized developer
composition, and LIG is a ligand capable of complexing with metal
ions, while joined to the polymer, to form a dye. These polymers
also have recurring units which impart hydrophilicity to the
polymer. These polymers form metal complex dyes in unexposed areas
of photographic elements only, while the ligand is cleaved from the
polymer in the exposed areas and washed out of the element.
Inventors: |
Washburn; William N. (Ionia,
NY), Hollister; Kenneth R. (Rochester, NY) |
Assignee: |
Eastman Kodak Company
(Rochester, NY)
|
Family
ID: |
24763607 |
Appl.
No.: |
06/688,224 |
Filed: |
January 2, 1985 |
Current U.S.
Class: |
430/367; 430/226;
430/359; 430/371; 430/375; 430/378; 430/381; 430/542; 430/548 |
Current CPC
Class: |
G03C
7/3275 (20130101); G03C 7/30547 (20130101) |
Current International
Class: |
G03C
7/327 (20060101); G03C 7/305 (20060101); G03C
001/40 (); G03C 007/32 () |
Field of
Search: |
;430/359,375,367,378,381,542,548,226,371 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
56-05543 |
|
Jan 1981 |
|
JP |
|
59-44773 |
|
Mar 1984 |
|
JP |
|
701843 |
|
Jan 1954 |
|
GB |
|
Other References
Research Disclosure, publication 17643, paragraph VII, Dec. 1978.
.
Schilt, Talanta, 13, pp. 895-902 (1966)..
|
Primary Examiner: Schilling; Richard L.
Attorney, Agent or Firm: Tucker; J. Lanny
Claims
We claim:
1. A photographic element comprising a support having thereon at
least one silver halide emulsion layer having associated therewith
an essentially colorless, hydrophilic ligand-releasing polymer
comprising
(a) recurring units derived from an ethylenically unsaturated
polymerizable hydrophilic monomer in a number sufficient to render
said polymer hydrophilic, and
(b) recurring units derived from an ethylenically unsaturated
polymerizable monomer represented by the structure: ##STR26##
wherein R' is hydrogen or lower alkyl,
COUP is a photographic color coupling moiety,
LINK is a coupling-off group which can be cleaved from COUP by an
oxidized developer composition, and
LIG is a ligand capable of complexing with metal ions, while joined
to said polymer, to form a dye in the unexposed areas of said
element.
2. The element of claim 1 further comprising a compound associated
with said emulsion layer which is capable, upon development, of
providing a dye image in exposed areas of said element.
3. The element of claim 1 wherein LIG is derived from a compound
having the structure: ##STR27## wherein m is 0 or a positive
integer of 1 to 3, n and p are independently 0 or 1, represents a
single or double bond,
Z is R.sup.1 --N.dbd., O.dbd., S.dbd., R.sup.1 --P.dbd.,
(R.sup.1).sub.2 P-- or (R.sup.1).sub.3 P.dbd., and when Z is
(R.sup.1).sub.2 P--, n is 1, otherwise n is 0,
R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are
independently hydrogen, amino, hydroxy, mercapto, alkoxy, alkyl,
aryl or a heterocyclic moiety, and when R.sup.6 is so defined, p is
1 and is a single bond,
if m is 0, R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, and R.sup.3
and R.sup.4, taken together, can independently represent the carbon
and heteroatoms necessary to complete a substituted or
unsubstituted carbocyclic or heterocyclic nucleus, or, if m is 1 to
3, R.sup.1 and R.sup.2, R.sup.5 and R.sup.6, and R.sup.3 and
R.sup.4, taken together, can independently represent the carbon and
heteroatoms necessary to complete a substituted or unsubstituted
heterocyclic nucleus, and when R.sup.5 and R.sup.6 are so defined,
p is 0 when is a double bond, and p is 1 when is a single bond.
4. The element of claim 3 wherein m is 0 or 1 and Z is R.sup.1
--N.dbd..
5. The element of claim 1 comprising a red-sensitive silver halide
emulsion unit having associated therewith a cyan dye
image-providing material, a green-sensitive silver halide emulsion
unit having associated therewith a magenta dye image-providing
material, and a blue-sensitive silver halide emulsion unit having
associated therewith a yellow dye image-providing silver halide
material, and wherein said ligand-releasing polymer is associated
with at least one of said units.
6. The element of claim 5 wherein said ligand-releasing polymer
provides a magenta dye in said unexposed areas when complexed with
metal ions.
7. The element of claim 1 wherein said ligand-releasing polymer
forms a dye with ferrous ions.
8. The element of claim 1 wherein said ligand-releasing polymer is
poly{{{N-{{4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-3-o
xopentanamido}phenyl}}acrylamide-co-sodium
2-acrylamido-2-methylpropane-1-sulfonate}}},
poly{{{N-{{4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-(4-pyridyl)phen
oxy]-3-oxopentanamido}phenyl}}acrylamide-co-sodium
2-acrylamido-2-methylpropane-1-sulfonate}}}, and
poly{{{{N-{{{4-chloro-3-{{4,4-dimethyl-2-{4-[6-phenyl-3-(2-pyridyl)-5-as-t
riazinyl]-phenoxy}-3-oxopehtanamido}}phenyl}}}acrylamide-co-sodium
2-acrylamido-2-methylpropane-1-sulfonate}}}}.
9. A process of dye formation in an imagewise exposed element of
claim 1, said process comprising the steps of:
a. developing the imagewise exposed areas of said element with a
color developing agent, thereby cleaving LINK-LIG from said polymer
and washing substantially all of cleaved LINK-LIG out of said
element, and
b. treating said element with metal ions to form a dye with said
ligand-releasing polymer in the unexposed areas of said
element.
10. The process of claim 8 wherein said metal ions are ferrous
ions.
Description
REFERENCE TO RELATED APPLICATIONS
This application is related to the following commonly assigned
applications, all filed on even date herewith: U.S. Ser. No.
688,477 by F. V. Lovecchio, J. A. Reczek and R. C. Stewart, U.S.
Ser. No. 688,478 by J. A. Reczek and J. M. Palumbo, and U.S. Ser.
No. 688,479 by W. N. Washburn.
FIELD OF THE INVENTION
This invention relates to color photography. In particular, it
relates to essentially colorless, ligand-releasing monomers and
polymers which can be used as masking dyes for color correction in
photographic elements or to form reversal images in photographic
elements. This invention also relates to such elements and to a
process for dye formation.
BACKGROUND OF THE INVENTION
It is known that dyes used in multicolor photographic elements do
not transmit all of the electromagnetic radiation desired by
theoretical photographic considerations. For example, the cyan dye,
which should absorb radiation in the red region and transmit
radiation in the green and blue regions of the electromagnetic
spectrum, usually absorbs a small amount of radiation in the latter
regions as well. The magenta and yellow dyes commonly used also
exhibit undesirable absorptions. The result of printing a
multicolor image formed with such dyes is to introduce undesirable
amounts of color image regardless of the printing process
parameters and sensitivity of the element. Color correction is
therefore desirable and is generally accomplished with masking in
some manner.
U.S. Pat. No. 2,449,966 (issued Sept. 21, 1968 to W. T. Hanson,
Jr.) and the art mentioned therein describe various means for color
correction of multicolor photographic elements, including the use
of preformed dyes. Research Disclosure, publication 17643,
paragraph VII, December, 1978 and references described therein also
describe color masking dyes. (Research Disclosure is available from
Kenneth Mason Publications, Ltd., The Old Harbourmaster's, 8 North
St., Emsworth, Hampshire P010 7DD, United Kingdom). However, the
compounds commonly used for color correction are already colored at
the time of imagewise exposure. If such dyes and silver halide are
incorporated in the same layer of a multicolor photographic
element, the dye will act as an unwanted filter, absorbing a
portion of the incident radiation which otherwise would reach
silver halide in underlying layers. This results in a loss of
sensitivity (i.e. photographic speed). One way to reduce this
problem is to put masking dyes in only one layer of the multicolor
elements, which generally have three color-forming layers. This
solution is not desirable if masking is needed in the other layers.
Another way to eliminate the unwanted filtering effect is to have
the silver halide and the dye in separate layers while maintaining
them in reactive association. While this is a useful and practical
solution, it increases the number of layers in the element, making
it thicker and presenting manufacturing and imaging
inefficiencies.
U.S. Ser. No. 688,479 of W. N. Washburn, noted above, describes
color masking dyes generated from ballasted colorless couplers
containing a coupling-off group which will generate a color masking
dye upon complexation with metal ions, e.g. ferrous ions. Although
polymeric compounds of this invention are broadly within the
description of the Washburn application, the focus of the Washburn
application and its examples is on nonpolymeric ligand-releasing
compounds. Although those compounds and the process of using them
represent a significant advance in the art, the nonpolymeric
ligand-releasing compounds described therein are difficult to
disperse in aqueous coating compositions, and therefore require the
use of coupler solvents to accomplish dispersion and coating.
However, coupler solvents reduce the rate of metallization (i.e.
complexation with metal ions) of the nonpolymeric colorless
ligand-releasing compounds in unexposed areas of the element.
Hence, in the time generally acceptable for processing of
photographic elements, less dye may be formed. To overcome this
deficiency, the elements can be subjected to an additional metal
ion bath treatment to increase the dye formation sufficiently.
Therefore, it would be highly desirable to have a means for dye
formation (e.g. color correction) in photographic elements which
would allow easy formulation of coating compositions and avoid
coupler solvents and the problems associated with them.
SUMMARY OF THE INVENTION
The present invention provides essentially colorless, hydrophilic
ligand-releasing polymers which provide an improved means of dye
formation, e.g. for color masking unwanted absorption. The elements
and process of using the polymers of this invention have all of the
advantages of the materials of the Washburn application noted
above, but in addition, they avoid the problems encountered with
coupler solvents.
In particular, the polymers of this invention allow for more
efficient dye formation by making the dye-forming ligand more
accessible to metal ions for complexation. Acceptable dye formation
can be achieved rapidly without the need for additional metal ion
bath treatments due to more rapid metallization. These advantages
are particularly important for color correction of unwanted
absorption in photographic elements. It is a further unexpected
advantage that the polymeric materials of this invention are
photographically active in the absence of coupler solvents and can
consequently be coated with less gelatin or other binders to
provide thinner layers and attendant improved image sharpness.
Therefore, in accordance with this invention, an ethylenically
unsaturated polymerizable monomer useful for preparing a polymer is
represented by the structure: ##STR2## wherein R' is hydrogen or
lower alkyl, COUP is a photographic color coupling moiety, LINK is
a coupling-off group which can be cleaved from COUP by an oxidized
developer composition, and LIG is a ligand capable of complexing
with metal ions, while joined to the polymer, to form a dye.
This invention also provides an essentially colorless, hydrophilic
ligand-releasing polymer comprises:
(a) recurring units derived from an ethylenically unsaturated
polymerizable hydrophilic monomer in a number sufficient to render
the polymer hydrophilic, and
(b) recurring units derived from an ethylenically unsaturated
polymerizable monomer represented above.
This invention further provides a photographic element comprising a
support having thereon at least one silver halide emulsion layer
having associated therewith the essentially colorless, hydrophilic
ligand-releasing polymer described above.
Further, a process of dye formation in an imagewise exposed element
like that described above comprises the steps of:
a. developing the imagewise exposed areas of the element with a
color developing agent, thereby cleaving LINK-LIG from the polymer
and washing substantially all of the cleaved LINK-LIG out of the
element, and
b. treating the element with metal ions to form a dye with the
ligand-releasing polymer in the unexposed areas of the element.
DETAILED DESCRIPTION OF THE INVENTION
The advantages described above for this invention are attained
because of the use of an essentially colorless, hydrophilic
ligand-releasing polymer as a dye-former. The polymers of this
invention are "essentially colorless", meaning that prior to
complexation of the LIG moiety with metal ions to form a visible
dye, the polymer exhibits essentially no observable color. That is,
the polymer exhibits a low optical density (i.e. less than about
0.05), although it may emit or reflect electromagnetic radiation in
the non-visible portions of the electromagnetic spectrum.
Therefore, the LIG moiety and the metal ions "form" a colored dye
from a colorless precursor, as opposed to compounds which are
merely shifted in their absorption .lambda..sub.max upon
complexation with a metal ion to provide a dye of a different
color.
The polymers of this invention are hydrophilic, meaning that they
are water-soluble or -dispersible (i.e. at least about 1 g of
polymer can be dispersed or dissolved in 100 ml of water). The
hydrophilicity of the polymers is provided by recurring units in
the polymer which are derived from one or more ethylenically
unsaturated polymerizable monomers which are hydrophilic in nature.
For example, the monomers can be nonionic (uncharged or amphoteric)
but have one or more uncharged solubilizing groups, such as
hydroxy, amide (substituted or unsubstituted), sulfonamide and
imino. Alternatively, the monomers can be anionic or cationic in
charge having one or more anionic or cationic groups thereon,
respectively. Such groups include but are hot limited to carboxy,
sulfo, phosphono, quaternary ammonium, and phosphonium groups.
These recurring units are present in the polymer in amounts
sufficient to render it hydrophilic as defined above. Generally,
the polymer contains from about 10 to about 90, and preferably from
about 40 to about 75, mole percent (based on total moles of
monomers polymerized), of such recurring units.
Representative monomers which provide hydrophilicity include
acrylamides and methacrylamides (e.g. acrylamide, methacrylamide,
N-isopropylacrylamide,
2-acrylamido-2-hydroxy-methyl-1,3-propanediol, etc.), hydroxyalkyl
acrylates and methacrylates (e.g. 2-hydroxyethyl acrylate,
2-hydroxypropyl methacrylate, etc.), carboxylic, phosphonic and
sulfonic acid containing monomers and their salts (e.g. acrylic
acid, methacrylic acid, itaconic acid, 2-acrylamido-2-methylpropane
sulfonic acid, 3-methacryloyloxypropane-1-sulfonic acid,
styrenesulfonic acid, vinyl sulfonic acid, and alkali metal and
ammonium salts of such acids, etc.), cationic salts, such as m- and
p-N-vinylbenzyl-N,N,N-trimethylammonium chloride,
N-(2-methacryloyloxyethyl-N,N,N-trimethylammonium methosulfate, and
others known to one skilled in polymer chemistry.
The polymers of this invention also comprise recurring units
derived from one or more ethylenically unsaturated polymerizable
monomers of this invention represented by the structure:
##STR3##
In this structure, R' is hydrogen or lower alkyl (substituted or
unsubstituted, preferably of 1 to 3 carbon atoms, e.g. methyl,
chloromethyl, ethyl, propyl, etc.). More preferably, R' is hydrogen
or methyl, and most preferably, it is hydrogen.
The recurring units derived from the illustrated structure above
are present in the polymer in amounts sufficient to provide desired
dye density when the LIG moiety is complexed with metal ions.
Generally, the polymer contains from about 10 to about 90, and
preferably from about 40 to about 75, mole percent (based on total
moles of monomers polymerized), of such recurring units.
COUP represents a photographic color coupling moiety derived from a
conventional color-forming coupler which yields a colored product
on reaction with an oxidized color developing agent, or which
yields a colorless product on reaction with oxidized color
developing agents. Both types of coupler moieties are well known to
those skilled in the art and described, for example, in Research
Disclosure, publication 17643, December, 1978, paragraph VII, and
references noted therein. Research Disclosure is available from
Kenneth Mason Publications, Ltd., The Old Harbourmastery's, 8 North
St., Emsworth, Hampshire P010 7DD, United Kingdom.
Examples of COUP moieties useful in the practice of this invention
include but are not limited to the following moieties which are
shown linked to LINK-LIG and having an unsatisfied bond where COUP
is attached to the polymer backbone either directly or through a
suitable linking group, such as an amide or ester linkage: ##STR4##
wherein r is 0 or 1, ##STR5## wherein q is an integer of 1 to 20,
##STR6## wherein R.sup.7 is substituted or unsubstituted alkyl
(preferably of 1 to 20 carbon atoms) or substituted or
unsubstituted aryl (preferably of 6 to 14 carbon atoms, e.g.
phenyl, naphthyl, p-methylphenyl, etc.), ##STR7##
LINK is a coupling-off group which can be cleaved from COUP by an
oxidized developer composition containing an oxidized color
developer. The coupling-off groups are generally heteroatoms or
heteroatom-containing linkages containing alkylene, arylene or
heterocyclic groups appended to the heteroatoms. Many such
coupling-off groups are known in the photographic art. Preferred
groups include --COO--, --CONH--, --O--, --S--, --SO.sub.2 O, and
--SO.sub.2 NH--. The timing groups described in U.S. Pat. Nos.
4,248,962 (issued Feb. 3, 1981 to Lau) and 4,409,323 (issued Oct.
11, 1983 to Sato et al) can also be used. An oxy group is a
particularly useful coupling-off group in the practice of this
invention.
LIG is a moiety, which when complexed with one or more metal ions,
forms a visible dye. This metal-LIG complexation occurs while LIG
is a part of the polymer in the unexposed areas of the element. In
exposed areas, LINK-LIG is cleaved from the rest of the polymer by
oxidized developing agent and substantially all of the cleaved
LINK-LIG moiety is subsequently washed out during processing.
Therefore, LINK-LIG is a moiety which is soluble enough to be
washed out of the element once it is cleaved from the rest of the
polymer. In the unexposed areas, the polymer is treated with metal
ions (e.g. ferrous ions) which complex with the uncoupled LIG
moiety to provide a visually colored dye.
Generally, the dyes formed upon complexation of the LIG moiety and
metal ions are visibly colored dyes. That is, they absorb
electromagnetic radiation in the so-called visible portion of the
electromagnetic spectrum, i.e. between about 400 and about 700 nm.
More than one molecule of a LIG moiety can be complexed with one
metal ion. For example, there may be two or three LIG molecules
complexed with a single metal ion. Representative dyes which can be
formed are cyan, yellow and magenta dyes.
Useful LIG moieties can be obtained from ferroin type compounds
such as hydrazones, tetrazolylpyridines, pyridylquinazolines,
bis-isoquinolines, imines, phenanthrolines, bipyridines,
terpyridines, bidiazines, pyridyldiazines, pyridylbenzimidazoles,
diazyltriazines, o-nitrosoanilines and phenols, tetrazines,
triazines described by Schilt et al in the journal Talanta, 15, pp.
475-478 (1968), pyridine derivatives of phenazine and quinoxaline
described by Schilt et al in Talanta, 15, pp. 852-855 (1968),
substituted benzimidazole derivatives as described by Schilt et al,
Talanta, 15, pp. 1055-1058 (1968), oximes of substituted methyl and
phenyl 2-pyridyl ketones as described by Schilt et al, Talanta, 16,
pp. 448-452 (1969), and the like. Other ligand-providing compounds
are described in the following Talanta literature articles: 16, pp.
519-522 (1969), 13, pp. 895-902 (1966), 17, pp. 649-653 (1970), 19,
pp. 1025-1031 (1972), 21, pp. 831-836 (1974), 22, pp. 915-917
(1975), 23, pp. 543-545 (1976), 24, pp. 685-687 (1977), 26, pp.
85-89 (1979), pp. 863-865 (1981), 36, pp. 373-376 (1979), 55, pp.
55-58 (1980), 29, pp. 129-132 (1982), and in Blandamer et al, J.
Chem. Soc. Dalton, pp. 1001-1008 (1978), and Case, J. Org. Chem.,
31, pp. 2398-2400 (1966). The terpyridines are particularly useful
for obtaining magenta dyes.
Particularly useful LIG moieties are those derived from compounds
represented by the structure: ##STR8## wherein m is 0 or a positive
integer 1 to 3, n and p are independently 0 or 1, represents a
single or double bond,
Z is R.sup.1 --N.dbd., O.dbd., S.dbd., R.sup.1 --P.dbd.,
(R.sup.1).sub.2 P-- or (R.sup.1).sub.3 P.dbd., and when Z is
(R.sup.1).sub.2 P--, n is 1, otherwise n is 0. Preferably, m is 0
or 1 and Z is R.sup.1 --N.dbd..
R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are
independently hydrogen, amino (primary, secondary or tertiary),
hydroxy, mercapto, alkoxy (preferably of 1 to 20 carbon atoms, e.g.
methoxy, chloromethoxy, ethoxy, octyloxy, alkoxy substituted with
imino, etc.), alkyl (preferably of 1 to 20 carbon atoms in the
nucleus, e.g. methyl, ethyl, chloromethyl, isopropyl, t-butyl,
heptyl, alkyl substituted with imino, etc.), aryl (preferably of 6
to 14 carbon atoms, e.g. phenyl, naphthyl, xylyl, p-methoxyphenyl,
aryl substituted with imino, etc.), or a heterocyclic moiety
(preferably having 5 to 20 carbon, nitrogen, sulfur or oxygen atoms
in the nucleus, e.g. pyridyl, quinolyl, a heterocycle substituted
with imino, etc.).
When R.sup.6 is a group defined above, p is 1 and is a single
bond.
Alternatively, if m is 0, R.sup.1 and R.sup.2, R.sup.2 and R.sup.3,
and R.sup.3 and R.sup.4, taken together, can independently
represent the carbon and heteroatoms (e.g. nitrogen, oxygen,
sulfur, selenium, etc.) necessary to complete a substituted or
unsubstituted 5 to 20 membered mono- or polycyclic carbocyclic or
heterocyclic group (e.g. pyridine, quinolyl, triazinyl,
phenanthrolinyl, pyrimidyl, etc.). The heterocyclic nucleus so
formed can be substituted with one or more oxo, alkyl, amino,
imino, aryl, phosphino (e.g. diphenylphosphino), alkoxy, amide,
sulfonamide, thio or sulfo groups as defined above, or a
heterocyclic group (e.g. pyridyl, pyrimidyl, thiazolyl, imidazolyl,
thienyl, etc.).
If m is 1, 2 or 3, R.sup.1 and R.sup.2, R.sup.5 and R.sup.6, and
R.sup.3 and R.sup.4, taken together, can independently represent
the carbon and heteroatoms (e.g. nitrogen, oxygen, sulfur,
selenium, etc.) necessary to complete a substituted or
unsubstituted 5 to 20 membered mono- or polycyclic heterocyclic
nucleus as defined above where m is 0. When R.sup.5 and R.sup.6 are
so defined, p is 0 when is a double bond, and p is 1 when is a
single bond.
Preferably, LINK-LIG is sufficiently soluble in processing
solutions that when it is cleaved from the rest of the polymer, it
can be washed out of the element. If desired, LIG can contain one
or more solubilizing groups, e.g. sulfate, sulfonate, carboxylate,
hydroxy or phosphate groups, to give it suitable aqueous
solubility.
Examples of useful LIG moieties which form dye complexes with
ferrous ions are shown below. In these structures, the point of
attachment to the polymer backbone through COUP-LINK is represented
by an unsatisfied bond. The .lambda..sub.max of each resulting
ferrous ion-complex dye is also noted, however, the
.lambda..sub.max can be shifted somewhat (e.g. 10-15 nm) depending
upon the polymer backbone to which LIG is attached.
______________________________________ ##STR9## yellow,
.lambda..sub.max = 442 nm ##STR10## yellow, .lambda..sub.max = 443
nm ##STR11## yellow, .lambda..sub.max = 441 nm ##STR12## magenta,
.lambda..sub.max = 564 nm ##STR13## red, .lambda..sub.max = 522 nm
##STR14## magenta, .lambda..sub.max = 536 nm ##STR15## magenta,
.lambda..sub.max = 552 nm ##STR16## magenta, .lambda..sub.max = 571
nm ##STR17## magenta, .lambda..sub.max = 567 nm ##STR18## magenta,
.lambda. .sub.max = 583 nm ##STR19## magenta, .lambda..sub.max =
557 nm ##STR20## cyan, .lambda..sub.max = 644 nm ##STR21## cyan,
.lambda..sub.max = 670 nm and ##STR22## cyan, .lambda..sub.max =
650 nm. ______________________________________
The polymers of this invention can also comprise recurring units of
one or more ethylenically unsaturated polymerizable monomers other
than those described above in quantities that do not adversely
affect hydrophilicity or dye-forming capabilities. The types and
amounts of such monomers which would be useful are within the skill
of a polymer chemist.
Representative polymers of this invention include the
following:
poly{{{N-{{4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-3-ox
opentanamido}phenyl}}acrylamide-co sodium
2-acrylamido-2-methylpropane-1-sulfonate}}},
poly{{{N-{{4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-(4-pyridyl)pheno
xy]-3-oxopentanamido}phenyl}}acrylamide-co sodium
2-acrylamido-2-methylpropane-1-sulfonate}}},
poly{{{{N-{{{4-chloro-3-{{4,4-dimethyl-2-{4-[6-phenyl-3-(2-pyridyl)-5-as-tr
iazinyl]phenoxy}-3-oxopentanamido}}-phenyl}}}acrylamide-co-sodium
2-acrylamido-2-methylpropane-1-sulfonate}}}}, and
poly{N-(4-acrylamido-2-chlorophenyl)-1-hydroxy-4-[2,6-di(2-pyridyl)-4-pyrid
yloxy]-2-naphthamide-co-sodium
2-acrylamido-2-methylpropane-1-sulfonate}.
The hydrophilic monomers useful in the practice of this invention
can be prepared using well known chemical reactants and procedures.
Most of them can be obtained commercially from a number of
sources.
The ligand-releasing monomers of this invention are not generally
available from commercial sources, but they can be prepared using
chemical reactions and reactants known to one skilled in
photographic chemistry and polymer chemistry. Generally, a compound
from which the LIG moiety is derived is first reacted with a
compound from which COUP is derived. A detailed synthesis of a
representative polymer is provided in Example 1 below.
In certain embodiments, the following general preparatory
techniques can be used:
(a) Reaction of a compound from which LIG is derived containing a
hydroxy group with a color coupler containing a leaving group (e.g.
halogen, tosylate, mesylate, sulfonium salt, etc.) in the coupling
off position to produce a COUP-LINK-LIG compound having an oxy LINK
group. Alternatively, a LIG moiety having a mercapto group can be
used to obtain a COUP-LINK-LIG compound. This compound is then
attached to a suitable ethylenically unsaturated polymerizable
monomer (e.g. acrylic acid) by reacting one of its functional
groups (e.g. amino) with a suitable pendant moiety (e.g. carboxy)
on that backbone to provide a ligand-releasing monomer.
(b) Reaction of a color coupler having a hydroxy or mercapto group
with a LIG moiety containing a leaving group to produce the same
kind of compound as described in (a).
In other embodiments, COUP-LINK-LIG can be prepared by condensation
of a LIG-containing carboxylic acid halide or sulfonic acid halide
with a color coupler containing a hydroxy, mercapto or amino group
in the coupling position to produce COUP-LINK-LIG wherein LINK is
an ester, amide, sulfonamide or thioester linkage. The resulting
COUP-LINK-LIG compound is then attached to a suitable ethylenically
unsaturated polymerizable monomer in a suitable manner to provide a
ligand-releasing polymerizable monomer with the releasable
ligand.
In still other embodiments, the LIG moiety can be attached to an
ethylenically unsaturated polymerizable color coupler monomer
having the general structure: ##STR23## wherein R' and COUP are as
defined above. The LIG moiety is attached to COUP through a LINK
group using similar reactions and procedures as described
above.
The ligand-releasing polymers of this invention can be prepared by
polymerizing the polymerizable monomers described above using well
known solution or emulsion polymerization techniques. Generally,
the polymers are prepared using free radical initiated reactions of
the monomers while either dissolved in one or more suitable
solvents as in solution polymerization, or as dispersed as
emulsions in water with a suitable surfactant in emulsion
polymerization. Suitable solvents for solution polymerization
include dimethylsulfoxide, N,N-dimethylformamide and
N-methylpyrrolidone. The details of a representative polymer
preparation are provided in Example 1 below.
Alternatively, a ligand-releasing polymer of this invention can be
prepared by reacting a polymeric color coupler with a suitable
compound from which LIG is derived using known techniques described
above.
As noted above, LIG is a moiety capable of complexing with metal
ions to provide desired dyes in one or more layers of photographic
elements. A variety of metal ions can be so used as long as the
complex of the LIG moiety with the metal ion is stable, or in other
words, the complex is likely to remain in complexed form for a
substantial period of time. In general, the formation constant of
such complexes should be in the range of from about 10 to about 30,
and preferably from about 15 to about 25. Useful metal ions include
Fe.sup.++, Co.sup.++, Cu.sup.+, Cu.sup.++, Ru.sup.++ and Os.sup.++.
Ferrous ions are preferred in the practice of this invention.
In the practice of this invention, cleavage of LINK-LIG from the
rest of the polymer results from reaction of oxidized developing
agent with the polymer. Any suitable developing agent, which when
oxidized from silver halide development will react with the
polymer, can be used in the practice of this invention.
Particularly useful developing agents are color developing agents,
including aminophenols, phenylenediamines, tetrahydroquinolines and
the like as described, for example, in Research Disclosure,
publication 17643, paragraph XX, noted above. Other useful
developing agents include hydroquinones, catechols and
pyrazolidones.
The photographic elements and film units of this invention can be
processed by conventional techniques in which the processing
solutions or compositions are incorporated in the element or are
separately applied in a solution or process sheet. These solutions
or compositions contain developing agents (e.g. color developing
agents) and other conventional processing addenda, as well as metal
ions to complex with LIG, if desired. Alternatively, the metal ions
can be incorporated within the element in the same or different
layer as the ligand-releasing polymer. More specifically,
processing of the elements of this invention can be accomplished by
treating an imagewise exposed element containing the polymer with
an alkaline processing solution containing a color developing agent
(and another developing agent, if desired) to form an imagewise
distribution of LINK-LIG moiety which is washed out of the element.
The ligand-releasing polymer in unexposed areas is treated with
metal ions to provide a dye in those areas. The ferrous or other
metal ions can be included in the bleach solution for complexation
with the polymer.
Photographic elements of this invention in which the described
polymers are incorporated can be elements comprising a support and
one or more silver halide emulsion layers. The polymers can be
incorporated in the silver halide emulsion layer or in another
layer, such as an adjacent layer, where they will come into
reactive association with oxidized color developing agent which has
developed silver halide in the emulsion layer. The silver halide
emulsion layer can also contain, or have associated with it,
photographic coupler compounds, such as color forming couplers,
etc. These coupler compounds can form dyes of the same or different
color or hue as the dyes formed by complexation of LIG and metal
ions. Additionally, the silver halide emulsion layer can contain
addenda conventionally contained in such layers.
In a preferred embodiment of this invention, the polymer of this
invention is used to provide a color correcting dye (or a color
masking dye as it is sometimes known in the art). The polymer can
be incorporated in a multilayer, multicolor photographic element
which comprises a support having thereon a red-sensitive silver
halide emulsion unit having associated therewith a cyan dye image
providing material, a green-sensitive silver halide emulsion unit
having associated therewith a magenta dye image providing material
and a blue-sensitive silver halide emulsion unit having associated
therewith a yellow dye image-providing material, at least one of
the silver halide emulsion units having associated therewith a
ligand-releasing polymer. Each silver halide emulsion unit can be
composed of one or more layers and the various units and layers can
be arranged in different locations with respect to one another as
is known in the art. The polymers described herein can be
incorporated into or associated with one or more units or layers of
the element. Preferably, the polymer can provide a magenta masking
dye in either the red-sensitive or blue-sensitive silver halide
emulsion units.
The light sensitive silver halide emulsions can include coarse,
regular or fine grain silver halide crystals or mixtures thereof
and can be comprised of such silver halides as silver chloride,
silver bromide, silver bromoiodide, silver chlorobromide, silver
chloroiodide, silver chlorobromoiodide and mixtures thereof. The
emulsions can be negative-working or direct-positive emulsions.
They can form latent images predominantly on the surface of the
silver halide grains or predominantly on the interior of the
grains. They can be chemically and spectrally sensitized. The
emulsions generally are gelatin-containing emulsions although other
natural or synthetic hydrophilic colloids, soluble polymers or
mixtures thereof can be used if desired.
The element support can be any suitable substrate used in
photographic elements. Examples of such supports include films of
cellulose nitrate, cellulose acetates, poly(vinyl acetal),
polyesters [e.g. poly(ethylene terephthalate)], polycarbonates and
other resinous materials, glass, metals, paper, and the like.
Generally, a flexible paper or resinous film support is used, and a
paper support is particularly useful. Paper supports can be
acetylated or coated with baryta and/or an .alpha.-olefin polymer
such as polyethylene, polypropylene, ethylene-butene copolymer and
the like.
In another embodiment of this invention, the polymer of this
invention can be used to generate a reversal image in an element
using what are known in the art as "universal" couplers. This can
be done by incorporating a ligand-releasing polymer in the element
wherein COUP of the polymer is a moiety which yields a colorless or
diffusible reaction product with oxidized developing agent and LIG
is as defined above. Upon imagewise development with a developing
agent, the dye-forming moiety of the polymer is cleaved from the
polymer backbone in exposed areas and washed out of the element.
Subsequent treatment of the element with metal ions provides dyes
in the unexposed areas to provide a reversal image.
Further details regarding silver halide emulsions and photographic
elements are well known in the art as described, for example, in
Research Disclosure, publication 17643, noted above.
The following examples are presented to illustrate the practice of
the present invention.
EXAMPLE 1--Preparation of
Poly{{{N-{{4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-3-o
xopentanamido}phenyl}}acrylamide-co-sodium
2-acrylamido-2-methylpropane-S1-sulfonate }}} (1:2.54 mole
ratio)
Preparation of Ligand-Releasing Monomer:
The following were added to a 100 ml flask equipped with a stirrer:
2.5 g (10 mmoles) of 2,6-di-2-pyridyl-4-hydroxypyridine, 2.5 ml (20
mmoles) of tetramethylguanidine, 50 ml of CH.sub.3 CN and 4.4 g (15
mmoles) of
4,4-dimethyl-2-chloro-N-(2-chloro-5-nitrophenyl)-3-oxopentanamide.
The resulting mixture was heated with stirring to 50.degree. C.
under nitrogen and then overnight at 20.degree. C. The solution was
concentrated, poured into water and the resulting yellow solid
collected by filtration. The filter cake was triturated with hot
benzene, then washed with dilute acetic acid. The resulting white
solid was recrystallized from ethyl acetate yielding 3.4 g. The
nuclear magnetic resonance and mass spectra were consistent with
4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-N-(2-chloro-5-nitrophenyl)
-oxopentanamide. This material was hydrogenated using a
conventional Parr shaker for 1 hour at 50 psi (about 3.45 bars) in
2:1 THF/acetone over platinum oxide. For every gram of the
pentanamide, 20 ml of solvent and 75 mg of catalyst were used. The
solution was filtered and the filtrate concentrated to give a white
solid (95%) which was determined by mass spectral analysis to be
4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-3-oxopentanami
do}aniline.
A 15 ml glass bottle was then charged with 1.29 g of
4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-3-oxopentanami
do}aniline and 6.45 g of acrylic acid. The clear, brown solution
which developed was stirred at ambient temperature as 0.314 g of
acryloyl chloride was added dropwise over a 2-minute period. After
stirring the resulting solution at ambient temperature for an
additional 15 minutes, it was treated with 0.29 g of sodium
acetate, sealed, and stirred an additional 4 hours. At this point
the bottle was opened and the red-brown slurry it contained was
treated with 10 ml of distilled water followed by titration with
25% sodium hydroxide. A sticky red-brown precipitate gradually
formed which was removed from time to time to allowing stirring.
Eventually, as the pH rose to 10, the removed precipitate was
dissolved in 30 ml of dichloromethane and that solution shaken with
the remaining aqueous mixture in a separatory funnel. Upon layer
separation the dichloromethane solution was subsequently washed
with two additional 20 ml portions of distilled water, dried over
magnesium sulfate, and the volatiles stripped at room temperature
on a rotary evaporator. The residue was 1.2 g of an ochre colored
product. The nuclear magnetic resonance spectrum was consistent
with the monomer,
N-{{4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-3-oxopenta
namido}-phenyl}}acrylamide.
Preparation of Polymer:
A 10 ml glass bottle was charged with 0.5 g of
N-{{4-chloro-3-{4,4-dimethyl-2-[2,6-di(2-pyridyl)-4-pyridyloxy]-3-oxopenta
namido}-phenyl}}acrylamide, 0.5 g of sodium
2-acrylamido-2-methylpropane-1-sulfonate, and 3.0 g of reagent
grade dimethylsulfoxide. Upon stirring, a clear red-brown solution
was formed which was then treated with 0.005 g of
2,2'-azobis(2-methylpropionitrile) polymerization initiator and
sparged with nitrogen for 40 minutes. The bottle was then immersed
in a 60.degree. C. bath and the sparging continued for 1 hour. It
was then sealed and kept at 60.degree. C. for an additional 3.5
hours. At this point the bottle was opened, another 0.005 g of
initiator added, sparged with nitrogen for 15 minutes, resealed,
and kept at 60.degree. C. overnight. The viscous, clear dope which
resulted was poured in a fine stream into 35 ml of stirring
acetone. The frangible precipitate which formed was readily broken
down into a powder. After washing it with five successive 35 ml
portions of acetone it was dried at room temperature under
nitrogen/vacuum. The dry tan powder which resulted comprised 0.80 g
of the desired ligand-releasing polymer.
EXAMPLE 2--Photographic Evaluation of the Polymer of Example 1
A 3:1 molar mixture of a conventional yellow dye-providing color
coupler having the structure: ##STR24## and the polymer of Example
1 was mixed with half their weight of dibutyl phthalate and three
times their weight of ethyl acetate. The above mixture became
homogeneous upon addition of aqueous gelatin. The coating levels on
a suitable support were 3.8 g/m.sup.2 of gelatin, 756 mg/m.sup.2 of
silver, 1.8 g/m.sup.2 of the conventional coupler and 764
mg/m.sup.2 of the polymer of Example 1. The resulting element
strips were stepwise exposed, developed using a conventional pH 10
color developer and bleached with a fresh solution of conventional
bleach. No masking dye scale was observed under these conditions
but seasoned bleach or dilute ammonium ferrous sulfate solutions
did generate the magenta color correcting dye scale. The
ligand-releasing polymer of this invention provided acceptable
color correction of the resulting developed element.
EXAMPLE 3--Comparative Example
This is an example comparing the metallization, or dye formation,
rates of a hydrophilic ligand-releasing polymer of this invention
to the rates of a nonpolymeric ligand-releasing compound described
in the Washburn application referenced above.
The rates of metallization of the polymer described in Example 1
were determined in a conventional ferric ethylene diamine
tetraacetic acid (EDTA) bleach at different ferrous ion
concentrations shown in Table I below and at pH 6.1. The resulting
ferrous ion concentrations in the bleach solutions correspond to
those normally encountered in conventional photofinishing
conditions. The extent of complexation was followed by measuring
the resultant magenta dye density at 560 nm. Samples of gelatin
(3.8 g/m.sup.2) coatings of the polymer (3.1 g/m.sup.2) on a
support were immersed in a sufficiently large amount (100 ml) of
each bleach solution to insure that the ferrous ion concentration
would not be changed as metallization occurred. The rate constants
are presented in Table I below as a function of ferrous ion
concentration.
TABLE I ______________________________________ Ferrous Ion
Concentration Metallization Rate (sec.sup.-1) (g/l) Polymer
______________________________________ 0.3 5.9 .times. 10.sup.-4
0.6 9.2 .times. 10.sup.-4 0.76 1.0 .times. 10.sup.-3 0.82 1.2
.times. 10.sup.-3 ______________________________________
A nonpolymeric ligand-releasing compound was similarly tested. This
compound had the structure: ##STR25## This compound (2.2 g/m.sup.2)
was coated with gelatin (3.8 g/m.sup.2) and dibutyl phthalate
coupler solvent on a suitable support.
Table II compares the rate of metallization of the nonpolymeric
ligand-releasing compound to the rate of the polymeric compound as
a function of pH.
TABLE II ______________________________________ Metallization Rate
Ferrous Ion (sec.sup.-1) Concentration (g/l) Polymeric Nonpolymeric
in Bleach* pH Compound Compound
______________________________________ 0.76 6.1 1 .times. 10.sup.-3
7.8 .times. 10.sup.-5 0.66 4.7 1.27 .times. 10.sup.-2 1.03 .times.
10.sup.-3 ______________________________________ *Conventional
ferricEDTA bleach described above.
When using a pH 6.1 aqueous ferrous sulfate solution (Fe.sup.+2
=0.02 g/l ) the nonpolymeric compound metallized 16 times more
slowly than the polymeric compound. For example, 74% metallization
was obtained in 15 seconds with the polymeric compound whereas 4
minutes were required for 74% metallization of the nonpolymeric
compound.
The invention has been described in detail with particular
reference to preferred embodiments thereof, but it will be
understood that variations and modifications can be effected within
the spirit and scope of the invention.
* * * * *